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Tiny CPU Boards

The Tiny CPU boards arrived yesterday from Seeed Studio’s Fusion PCB service. Now it’s time to break out my soldering iron again, and get busy with that 0.5 mm pitch 100-pin TQFP. Ugh!

I placed the order with Seeed on June 6, and received the boards on June 23, so that’s 17 days of calendar time from order to mailbox. Considering how slow shipping from China can be, I’m pretty happy with that. It’s actually not much slower than the 12 day turn-around time I got from Dorkbot PDX’s PCB service, which is done in the USA.

The Tiny CPU board is 100mm x 80mm, or about 12.4 square inches. For 10 boards with 50% e-test, the cost was $25 plus about $7 for shipping. I actually received 12 boards instead of the promised 10. Five boards were taped together and marked with a black line down the edge, so I assume those are the ones that were e-tested. The other seven boards were stacked on top, then the whole bundle of 12 boards was shrink-wrapped, packed in bubble wrap, and packed in a small box for shipping.

The quality of the boards looks pretty good, especially considering the dirt cheap price. Drill holes look nicely centered, and tracks look neat and clean. It’s not all perfect though, and the overall quality level feels a bit less than the Dorkbot PDX boards. There’s a bit of variation in soldermask and plating from board to board, and some of the boards look pretty scuffed up. There are also some odd numbers and a line that were added to my silkscreen layer, which I could do without.

Um, what the heck is 35186H2 and 01895Q-10? And moreover, what is that curved arc in the silkscreen layer extending from LED1 all the way to the board’s edge? None of that appears in my top silkscreen Gerber. It’s not a huge deal to have some random extra numbers and lines, it doesn’t affect anything of course, but it’s a bit annoying.

Two of the boards have some pretty significant damage from scraping or impact. I’m not sure if it’s enough to cause a failure, but it definitely might. One board is damaged on the top, and the other on the bottom, and when you stack them the damaged spots overlap. I’m guessing some sharp object got caught between these two boards, and ground away the soldermask where it rubbed against them. Maybe this is why I got 12 boards instead of 10?

I tented my vias with soldermask this time, or tried to anyway. In theory, 100% of the vias should be tented. In practice, most of the vias are tented, but some aren’t, and the fraction of tented vias varies quite a bit from board to board. Here’s the same section from two different boards, where one is 100% tented and the other is maybe 25%.

Overall I’m fairly happy with these Seeed PCB Fusion boards: decent build quality and cheap pricing. Yes, there are a few dinged and damaged boards, but given the total number of boards for the price (and the two bonus boards I received), I can call those throw-aways and still have a good deal. I would certainly use them again. For smaller boards where the costs are comparable, though, I would favor Dorkbot PDX’s PCB service, since it’s a few days faster and seems to be a bit higher quality.

Read 7 comments and join the conversation 

7 Comments so far

  1. Diego Spinola - June 30th, 2011 6:50 am

    I’ll be sending my first orders to them next month

    Thanks for the review =)


  2. […] Mess o’ Wires has a review of our Fusion PCB Service, it would help us to improve ourselves and also may help you to get more understanding of what we […]

  3. George - August 4th, 2011 11:39 am

    I’ve used Seeed several times, and had no real complaints. Certainly nothing worse than I’ve received from other sites; I have some much, much worse silkscreen problems than that inexplicable arc shown above.

    One oft-overlooked strength of Seeed is their volume pricing, should you ever need moderate quantities of something. Their 5x10cm service is ~$75 at quantity 50. Supposing you needed 50 2×3″ PCBs, Seeed is around $82 with shipping, while DorkbotPDX would be $300 with the introductory medium-run pricing, just over $500 at the regular price. (MakePCB, my usual go-to fab house for production boards, would be a bit over $100, depending on the exchange rate… but they’re also gold-plated.)

    The Dorkbot boards *are* undoubtedly nicer… but $218 nicer?

  4. […] Image credit: Big Mess o’ Wires […]

  5. B.Stott - December 26th, 2011 1:55 pm

    From the look of your strange numbers on your board. Check to see what your customer ID is? 35186H2 and what your Order number is? 01895Q-10. I guessed that the second number was your order number based on Q-10 being Quantity 10 which would likely be your customer number being the first. I’d not mind this on my boards. The arc is different though. But, as you point out the pricing is very good…. I’ll look to use them for small quantities beyond my one off test through DorkbotPDX. Thanks for your review…. B.Stott – Pittsburgh.

  6. […] Image credit: Big Mess o’ Wires […]

  7. kevenlaker - November 19th, 2014 6:52 pm

    Ordering PCBs from elecfreaks is awesome experience. $9.9 for 10 PCBs and you can choose your own color.

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